Ignition distributor



Sept. 27, 1949. A. c. WALL 2,483,115

IGNITION DISTRIBUTOR Filed Nov. 21. 1945 am so 21 1949" IGNITION ms'ramu'roa Alexander C. Wall, Indianapolis, Ind., asslgnor to P. R. Mallory & 00., Inc., Indianapolis, Ind., a corporation of Delaware Application November 21, 1945, Serial No. 630,069

8 Claims. (Cl. zoo-2e) This invention relates to electrical switches and particularly to distributor switches for ignition systems.

An object of the invention is to improve the construction of electrical switches and distributors.

Other objects of the invention will be apparent from the following description and accompanying drawings taken in connection with the aping of the brush or contact arm as it moves around the track resulting in rapid and uneven wear of the distributor parts. In accordance with pended manna this invention, a contact roller is provided which The invention comprises the features of conrides upon a continuous smooth track of wearstruction, combination of elements, arrangement resistant material thus insuring smooth operaof t and methods of manufacture referred tion of the distributor and freedom from oscilto above or which will be brought out and exlation or bouncing. The contact roller succesemplified in the disclosure hereinafter set forth, Sivoly ngages a plurality of sets of contacts as including the illustrations in the drawings, the t travels around the track, each set comprising scope of the invention being indicated in the apa pair of contacts disposed at opposite sides pended manna of the track and adapted to be bridged by the In th dyawjngs: roller. Although these contacts initially pro- Figure 1 is a front view of a distributor switch trude inwardly beyond the track surfa t a embodying the principles of this invention with ght extent, the roller works the contacts down parts broken away to show the detailed features until, after a short period of operation, they are of construction; at substantially the same level as the circular Figure 2 is a sectional view taken along the t ack. At this time, the contacts are still in line 2-2 of Figure 1; p s to be en a ed by the roller but the Figure 3 is an enlarged view of a. portion of pressure of the roller on the contacts is very the distributor switch shown in Figure 1; small so that the wear thereon s eatly de- Figure 4 is a sectional view taken along the creased. An additional feature of the invention line 4-4 of Figure 3; resides in the fact that the contacts are me- Figure 5 is a sectional i of t roller used 30 chanically separated from the track and from in the distributor shown i Figure 1; d each other so that there is little or no danger Figure 6 is a diagrammatic view illustrating of metallic particles becoming lodged in the track modifi ation of t invention, which might affect the timing of the distributor This invention is principally concerned with an c use o nc ng. electrical switch construction for successively e d s tor type switch of this invention making a plurality of electrical contacts. Such 15 particularly useful in eq en y ion a switch is particularly useful in ignition sys- Systems e in Voltages as high as. ,200 volts tems for operating the spark plug circuits of are often used. The novel track and contact aran engine in proper sequence as well as in varirangement affords ample contact area for reliaous other applications such as the control of 40 ble operati n nd p rkin i ubstantially elimielectric signs, testing circuits and the like. mated with resultant freedom from radio noise While a preferred embodiment of the inveninterference. tion is described herein, it is contemplated that Referring now to the drawings in detail, the considerable variation may be made in the methd s t r type switch may compr se a pp od of procedure and the construction of parts ing structure In which includes an inner circuwithout departing from the spirit of the invenla-r wear-resistant track H. The track is p tion In the following description and in the erably formed from a S t sulating comclaims, parts will be identified by specific names pound having hi h r nce to wear, such for for convenience, but they are intended to be as example a tehe structure I may e generic in their application to similar parts as flanged as at ilto provide shoulders at the ret t ll m t, spective opposite sides of the track for accom- Distributor switches previously constructed modating contact members in the manner herehave oftentimes utilized a rotatable contact inafter described. Annular plates l3 and II of brush which passes over a track, suitable coninsulating material are secured in any suitable to manner to the supporting structure It, the centacts being spaced at intervals alo g t e t d.

3 tral openings in said plates being of greater diameter than the track II. The plates II, ll carry a plurality of contact sets l5 which are preferably spaced at equal intervals around the track H. Each set comprises a pair of spring fingers or contacts l6, II which are supported, respectively, by the plates l3 and N. A contact portion 18 of each finger extends inwardly toward the track H and is closely spaced with respect to the adjacent shoulder l2 and the track. Each contact It may be connected to a suitable terminal or binding post l6 which, in turn, may extend to a spark plug excitation circuit or any other circuit to be energized. The contacts I! may be interconnected by a conductor plate I! interposed between said contacts and the insulation member l4 and this plate may be provided with a terminal or binding post I. for connection to an external circuit. The use of the plate I9 is optional, however, as it will be a short distance for a purpose to be hereinafter explained.

The switching mechanism is driven by a shaft which may be suitably connected to the drive shaft of anengine or to any other switch-actuating device. An arm 26 fixed on the shaft 25 has a roller carriage 21 pivoted thereto as at 28. A roller 29 is journaled in the carriage and urged into engagement with the track II by a spring 30 which is suitably secured to the arm 26 and the carriage 21. The roller 29, as best shown in Figure 5, comprises a ring or cylinder of conductive material which is adapted to successively bridge the fingers l8, ll of each contact set as the roller travels around the track. The cylinder 35 is fixed on a. pair of complementary sleeves 36, 31 of Bakelite or other insulating material which define a cylindrical passage within which is inserted a tube 38 of hardened metal. Suitable needle bearings 39 may be provided at the opposite ends of the tube in order to journal the roller in the carriage 31.

As the shaft 25 is rotated, the roller 29 successively engages and bridges the contact sets l5 to thereby close the circuits associated therewith. As previously stated, the contact portions [8 initially protrude inwardly beyond the track. After a short period of operation, the contact portions l8 are worked down until they extend inwardly of the track only a suflicient distance to be contacted by the roller 29. When the contacts are in this position, the roller exerts very little force thereon during operation of the distributor so that the wear on the contacts is greatly decreased. I indicate this relative position of the contact portions and the track by the pharse substantially level in the appended claims. The described construction has the advantage that the contacts may be made of ductile material so that wearing away of the contact surface is substantially eliminated while the surface of the track may be formed from hard wearresistant material so that it can withstand the operation of the roller. Moreover, it will be apparent that a smooth continuous surface is provided for on the roller so that bouncing or oscillation. thereof with resultant faulty operation of the distributor is avoided.

In the modification of the invention shown in Figure 6, a sliding contact 40 rather than a roller is utilized for engaging and bridging the contact 4 sets ii. The contactor is supported by a leaf spring ll from an arm 42 which is suitably attached to the drive shaft. Consequently, the spring urges the contact 40 into engagement with the track, the modified form operting in substantially the same manner as the apparatus shown in Figure 1 when the driveshaft is rotated.

In some cases, a common connection to the contacts may be made through the shaft and roller assembly. In such a construction, the contacts at one side of the device may be eliminated and the roller construction modified so that the current passes through the shaft and the roller to successively energize the contacts at the other side of the switch. It will be apparent that the construction may be modified so that the contacts and the circular track are disposed in a common plane, if desired, with the contacts of each set being disposed in radial alignment at opposite sides of the track.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it it not desired to be limited thereby but it is intended to cover the invention broadly within the spirit and scope of the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a switching device for successively closing a plurality of contacts, a circular track having an inner insulative wear-resistant surface, a rotatable contact assembly comprising a roller centralized with respect to said track adapted to travel on said wear-resistant surface, a spring member for urging said roller into engagement with said surface, and a plurality of contact sets spaced at equal intervals around the track on opposite sides thereof, each set comprising a pair of resilient contact members disposed at opposite sides of the track, each contact member having an arcuate portion adjacent and at substantially the same level as the track for engagement with said roller as it rotates around the track.

2. In a distributor for successively closing a plurality of spark plug circuits, a circular track having an inner wear-resistant and non-conducting surface, a rotatable contact assembly comprising a roller centralized with respect to said track adapted to travel on said wear-resistant surface, and a plurality of contact sets spaced around the track, each set comprising a pair of contacts dispoud at opposite sides of the track, each contact comprising a resilient portion protruding inwardly of the track for engagement with the roller, said inwardly-protruding portions becoming substantially level with the surface of the track after a period of operation of said distributor whereby the pressure of the roller on the contacts is negligibly small as compared to the centrifugal force of the roller against the surface of the track.

3. In a distributor for successively closing a plurality of spark plug circuits, a, circular nonconductive track, a plurality of contact sets spaced around said track, each set comprising a pair of contacts disposed at opposite sides of the track on opposite sides thereof, each contact having a conductive surface substantially level with the surface of the track at all times, and a contactor adapted to travel around the track to successively engage and bridge the contact sets, the portion of the track which is engaged by the contactor having a smooth wear-resistant surface of an immovable nature to prevent bouncing of the contactor thereon whereby substantially all the pressure exerted by said contact member is directed against said track and negligible pressure is exerted against said contacts.

4. In a distributor for successively closing a plurality of spark plu circuits, a circular insulating track, a plurality of contact sets spaced around said track, each set comprising a pair of contacts disposed at opposite sides of the track. each contact having a conductive surface Drotruding inwardly from the surface of the track, and a contactor adapted to travel around the track to successively engage and bridge the contact sets, the portion of the track which is engaged by the contactor having a smooth wearresistant and insulating surface to prevent bouncing of the contactor thereon, said inwardlyprotruding surfaces becoming substantially level with the surface of the track after a period of operation of said distributor whereby the pressure of the roller on the contacts is negligibly small as compared to the centrifugal force of the roller against the surface of the track.

5. In a distributor, a supporting structure comprisin a circular track formed from wear-resistant material, a plurality of contacts spaced around said track on opposite sides thereof in equal numbers and adapted for connection to the respective energizing circuits of a plurality of spark plugs, said contacts being substantially level with the surface of said track, a contact member adapted to travel on said track and successively engage said contacts and bridge opposite ones to thereby energize said circuits, and means for supplying current to said contact member when it is in engagement with said contacts.

6. In a distributor, a. supporting structure comprising a circular track formedfrom wear-resistant material, a plurality of contact sets secured to said structure and spaced around said track, each set comprising a pair of contacts disposed at opposite sides of the trackfeach contact having a portion which is substantially level with said track, the contacts at one side of the 4 track being adapted for connection to the respective energizing circuits of a plurality of spark plugs, the contacts at the other side of the track being connected together whereby current may be supplied to said interconnected contacts from a common source, and a contact roller adapted to travel on said track and successively bridge said contact sets to thereby energize said circuits, the

5 pressure of the roller on the contacts being neglil wear-resistant material, a plurality of contact sets secured to said structure and spaced around said track, each set comprising a pair of contacts disposed at opposite sides of the track, each contact having a portion which is substantially level with said track, a shaft at the center of said track having an arm thereon, a carriage pivoted on said arm having a roller journaled therein, and a spring member for urging the roller into engagement with said wear-resistant track, said roller being adapted to ride on the track as the shaft is rotated and successively bridge said sets of contacts.

8. In a switching device for successively closing a plurality of contacts, an inner track having a circular wear-resistant and insulative surface,

a contact roller centralized on said track and adapted to travel on said surface, and a pinrality of contact sets spaced around the track on opposite sides thereof in equal numbers, each set comprising a pair of ductile conductive contact members substantially level with the surface of the track, adapted to be bridged by said roller as it rotates around the track, the pressure of the roller on the contacts being negligibly small as compared to the centrifugal force of the roller against the surface of the track.

ALEXANDER C. WALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 858,956 Clarke July 2, 1907 1,264,933 Hersee May '7, 1918 1,469,032 Barker Sept. 25, 1923 1,547,261 Olshei July 28, 1925 

